/**
 * 广寒宫
 * 网址:www.guanghangong.xyz
 */
package org.moon.framework.autoconfigure.springmvc;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;

import javax.servlet.Filter;


/**
 * springmvc 公共依赖
 * @author moon
 */
@Configuration
public class SpringMvcAutoConfiguration {

	/**
	 * 请求头里添加requestId
	 * @return
	 */
	@Bean
	public Filter preRequestFilter() {
		return new PreRequestFilter();
	}

	@Bean
	@Primary
	@ConditionalOnMissingBean(ObjectMapper.class)
	public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder){
		ObjectMapper objectMapper = builder.createXmlMapper(false).build();

		// 通过该方法对mapper对象进行设置，所有序列化的对象都将按改规则进行系列化
		// Include.Include.ALWAYS 默认
		// Include.NON_DEFAULT 属性为默认值不序列化
		// Include.NON_EMPTY 属性为 空（""） 或者为 NULL 都不序列化，则返回的json是没有这个字段的。这样对移动端会更省流量
		// Include.NON_NULL 属性为NULL 不序列化,就是为null的字段不参加序列化
		objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);

		// 字段保留，将null值转为""
//        objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>(){
//        @Override
//        public void serialize(Object o, JsonGenerator jsonGenerator,
//                              SerializerProvider serializerProvider)
//                throws IOException, JsonProcessingException
//        {
//            jsonGenerator.writeString("");
//        }
//    });
		return objectMapper;
	}
}